Gary Johnson's presidential campaign may have taken a huge, embarrassing hit.

During an interview on MSNBC on Thursday, the Libertarian Party candidate asked "What is Aleppo?" when asked what he would do about the war-torn city in Syria that came into sharp focus recently after this horrifying image of a boy went viral.

After Mike Barnicle, who was part of the panel interviewing Johnson, got the former New Mexico governor up to speed, Johnson tried to do his best to give an answer. "With regard to Syria, um, I do think that it’s a mess,” Johnson said. “I think that the only way that we deal with Syria is to join hands with Russia to diplomatically bring that at an end.”

Johnson, who is running with former Massachusetts Governor William Weld, has been portraying himself as a viable third-party alternative for voters who are disenchanted with Donald Trump and Hillary Clinton. He needs to get 15% in several polls in order to appear at the upcoming debates, but this lack of knowledge about an international dilemma like Syria may seriously hurt his image and turn off constituents.

Johnson wasted no time in admitting his flub.

Whether or not voters let this incident pass remains to be seen, but #WhatIsAleppo quickly started trending on Twitter, with people both bashing and supporting Johnson.